Topical cosmetic skin lightening compositions that are safe and effective are particularly desirable for treating undesirable skin pigmentation, including for example, regional hyperpigmentation caused by melanocytic hyperactivity such as idiopathic melasma occurring during pregnancy (mask of pregnancy or chloasma) or secondary to estrogen-progesterone contraception; local hyperpigmentation caused by benign melanocytic hyperactivity and proliferation such as lentigo senilis, known as liver spots; accidental hyperpigmentation such as post-lesional photosensitization and scarring; skin ageing (for example lentigines seniles); and certain forms of leukoderma such as vitiligo where, if the injured skin cannot be repigmented, the residual zones of normal skin are lightened or depigmented to impart a homogeneous color to the entire skin.
Several active ingredients and preparations that lighten skin, i.e., counteract skin pigmentation, are currently known. These products that are currently used contain hydroquinone, but such products have recently been deemed unacceptable for toxicological reasons. In fact, RDC 215 forbids the use of hydroquinone in cosmetic products after December, 2007.
U.S. Published Patent Application No. 2008/0050459 describes a cosmetic composition comprising an extract of Phyllanthus Embilica, an extract of Bellis Perrenis, an extract of Glycyrrhiza Glabra, and requiring at least one oligopeptide to achieve its cosmetic effect for the combined cosmetic treatment of fine lines and wrinkles, and/or skin brightening. Suitable oligopeptides are described as those having a suitable molecular weight so that they are able to act as carriers of Phyllanthus Embilica extract and penetrate skin to maximize the efficacy. The only oligopeptides described in the publication for achieving the cosmetic composition are oligopeptide-4 (pro-collagen oligopeptide) and oligopeptide-5 (pro-elastin oligopeptide).
There remains a need in the art for improved topical cosmetic compositions containing agents that safely and effectively lighten skin.